1. Technical Field
The present invention relates to image reading apparatuses such as flatbed scanners.
2. Related Art
Thus far, there have been scanners, which are a type of image reading apparatus, in which a carriage that moves in the main scanning direction supports a reading sensor for reading an image of a document, and a motor for moving the carriage is provided in the scanner (for example, see JP-A-2004-54283).
In the scanner disclosed in JP-A-2004-54283, a pinion that is rotated by the motor is mounted in the carriage, and a rack that engages with the pinion is provided in the main apparatus unit itself. Accordingly, the carriage moves in the main scanning direction as a result of the motor being driven when the pinion and the rack are engaged with each other.
Incidentally, with such a carriage, there are cases where the pinion separates from the rack while the pinion is rotating. Accordingly, with the scanner disclosed in JP-A-2004-54283, the pinion is suppressed from separating from the rack by causing a guide member that is provided in the carriage to make contact with the rear surface of the toothed face of the rack.
However, in this case, momentum is generated central to the point of engagement between the pinion and the rack, and there is thus a problem in that areas at both ends in the lengthwise direction of the carriage, which is orthogonal to the main scanning direction, will become tilted. As a result, the reading sensor will also become tilted when the carriage is moving, resulting in the risk of images being read in a tilted state.